PRELIM LEC: Quality Assurance (TRANSES) Flashcards
TRANSES AND NOTES
Overall program that ensures that the final
results reported by the laboratory are correct
Quality Assurance
It is concerned with all factors that affect the test results from preanalytic, analytic and post-analytic phases
Quality Assurance
System of ensuring accuracy and precision in the lab
Quality Control
Process of ensuring that analytical results are correct
Quality Control
QC samples are measured periodically in the
same manner as clinical samples
Quality Control
Objectives of Quality Control:
- To check the stability of the machine
- To check the quality of the reagent
- To check for technical/clerical error
Types of Quality Control:
Intralab
Interlab
AKA Internal Quality Control
Intralab
Analyses of control samples
together with patient specimens
Intralab
Important in daily monitoring
Intralab
AKA External Quality Control
Interlab
Involves proficiency testing
programs
Interlab
Ex.: National External Quality
Assessment Scheme (NEQAS)
Interlab
Under RIPN
Interlab
Sends out specimen to labs to test, results are sent back, and results are compared
Interlab
Characteristics of an Ideal QC Material
- With known analyte concentrations
- Inexpensive and stable for long periods
- No communicable diseases
- No matrix effect
- Convenient packaging for easy dispensing and storage
- Resembles human sample
Maintain long-term accuracy of
methods
Interlab
TYPES OF REAGENTS
- Reagent Blank
- Standard
- Control
Value will tell the conc. of the
unknown
Standard
Reagent without any analyte
added
Reagent Blank
Most specific analytical solution
Standard
Only one analyte
Standard
Resembles patient sample
Control
Value will determine accuracy and
precision
Control
Many analyte
Control
Done on sick or ill individuals
Basis for treatment
More accurate, more expensive
Diagnostic Test
Done on apparently healthy
individuals
Not a basis for treatment
Less accurate, less expensive
Screening Test
QUALITY CONTROL PARAMETERS:
Validity
Refers to how well the test measures what it is supposed to measure.
Validity
It refers to the accuracy of the test, meaning how close the result is to its true value.
Validity
Refers to how well the test performs in use over time
Reliability
It refers to the precision of the test, meaning how close are the results of a test on repetition or how close the values are from one another.
Reliability
Indicating a person has the
disease when, in fact, he or she
does
True positive (TP)
Indicating a person does not have
the disease when, in fact, he or she
does
False negative (FN)
Indicating a person has the
disease when, in fact, he or she
does not
False positive (FP)
Indicating a person does not have
the disease when, in fact, he or she
does not
True negative
(TN)